1. Field of the Invention
There is substantial interest in the ability to detect the presence of various blood factors involved with the formation or inhibition of clotting. Two of the classical procedures involve the use of genetically deficient plasmas or mixtures of coagulation factors deficient in one essential factor and in one case assaying the formation of a clot using a variety of physical techniques. In the other case specific synthetic substrates for individual coagulation factors are employed, where such factors are enzymes or modulate the activity of enzyme factors. These techniques suffer from numerous deficiencies, in being expensive, requiring technical skills, in performing the assay, and difficulties in the obtaining and/or preparation of reagents.
There is, therefore, a significant need for providing rapid and efficient assays capable of automation for the detection of blood factors. In addition, despite the large number of immunoassays which are presently available with varying protocols and labels, there is still interest in providing assays which allow for high sensitivity, rapidity, and which are capable of detecting a wide variety of analytes of interest.
2. Description of the Prior Art
CRC Handbook Series in Clinical Laboratory Science (Seligson, ed.-in-chief), Section I: Hematology, Vol. III (Schmidt, ed.), 1980, concisely summarizes assays of individual factors. The use of synthetic substrates is described in Fareed et al., Clin. Chem. (1983) 29:225-236. The following report that fibrinogen binds extremely tightly to plastic surfaces: Parsons, Meth. Enzymology (1981) 73:224-239; Pesce, Biochim. Biophys. Acta (1977) 492:399-407; and Morrisey, Ann. N.Y. Acad. Sci. (1977) 283:50-64. The following report that fibrinogen bound to plastic may serve as a matrix for fibrin deposition: Ihlenfeld and Cooper, J. Biomed. Mat. Res. (1979) 13:577-591 and Packman et al., J. Lab. & Clin. Med. (1969) 73:686-697.